wait, are you going to be in Dallas or Killeen?
If you are in Killen just go to Granger. Its 10,000 acres total about 6,000 huntable broken into multiple hunting units surrounding the lake. Its open year round for hog archery hunting except for a handful of days in Sept/Oct when they do deer hunts. Its also closed when they bring in the helos to shoot hogs in an effort to get the hog numbers down (usually Jan)
This place is army corp but its managed by Texas Parks and wildlife. You will need the $48 APH.
Also for the hunts mentioned above in addition to all the other stuff I mentioned you will need a 5 day nonresident special hunting LICENSE for an additional $48.
Also, dont kill any random critters (rattlesnakes, etc). These places allow you to come hunt hogs b/c they want the hogs dead. Not b/c they want to give us a fun hunting venue.